The present invention relates to electrostatic motors and in particular to a drive providing electrical power to an electrostatic motor.
Electrostatic motors operate by exploiting forces generated by electrical fields on a respective stator and rotor, for example, as established on opposed plates on the stator and rotor. Electrostatic motors may be distinguished from conventional electromagnetic motors which exploit forces generated by interacting magnetic fields generated by the stator and rotor, for example, generated by current-carrying electrical coils or a permanent magnet.
Synchronous electrostatic motors are a class of electrostatic motors that provide a rotor presenting a substantially static electrical polarization which causes the rotor to rotate synchronously with a rotating electrostatic field generated by the stator. The stator generates this rotating electrostatic field by applying different phases of a periodic voltage to a set of circumferentially or axially displaced electrodes.
Electrical power to the stator, producing the desired rotating electrostatic field, may be generated, for example, by means of a high-voltage, three-phase, sinusoidal power from a generator applied to appropriately phased stator electrodes. Electrical power may also be synthesized by a step approximation or by pulse width modulation synthesis using high-voltage transistors to switch different polarities of electrical voltage among the stator electrodes. Current methods of controlling electrostatic motors provide relatively primitive control of torque and speed resulting in unnecessary power consumption or unutilized capability.